Unit 2 Lecture Notes

Question 1

Why do cells replicate (divide)?

Answer 1

Reproduction, growth and development, tissue renewal (bone marrow r and w blood cells)

Question 2

How is genetically material organized?

Answer 2

• chromosomes
• somatic cells
• gametes

Question 3

Chromatin includes what

Answer 3

DNA proteins

Question 4

Somatic cells undergo what

Answer 4

Mitosis

Question 5

Somatic cells

Answer 5

All cells besides sperm and eggs

Question 6

Gametes

Answer 6

Sperm and egg

Only 23 chromosomes

Question 7

What are the phases of the cell cycle?

Answer 7

G0, Interphase (G1,S,G2), Cytokinesis, Mitotic (M) phase

Question 8

G0

Answer 8

Resting phase

Question 9

G1

Answer 9

Undergoing process towards S phase (unreplicated chromosomes)

Question 10

G2

Answer 10

Cell with duplicated chromosomal getting machinery ready to undergo mitosis

Question 11

S

Answer 11

DNA synthesis

Question 12

What are the two cell cycle checkpoints and what happens during them?

Answer 12

G1 checkpoint: cell receives a go ahead signal

G2: cell does not receive a go ahead signal

Question 13

What does the G1 checkpoint check for?

Answer 13

Adequate cell size, nutrients sufficient, DNA undamaged

Question 14

During the G2 checkpoint what happens?

Answer 14

Chromosomes have replicated, DNA replicated, DNA un damaged, MPF activate and present (protein cyclinCDK complex)

Question 15

What happens during the M checkpoint

Answer 15

Chromosomes attached to spindle, chromosomes segregate, MPF absent

Question 16

What molecules turn the cell cycle on and off?

Answer 16

MPF contains a protein kinase (CDK) and a cyclin

Question 17

Regulation of the cell cycle

Answer 17

• the G2-M cyclin CDK regulates entry into M
• the M cyclin-cdk regulates process through mitosis
• restriction point (R)
• the G1 phase cyclin-CDK regulates entry into the cell cycle at R
• the S cyclin-CdK regulates repair of errors in DNA replication

Question 18

If DNA is damaged (blank) can bind G-S 1 CDK preventing activation by cyclin which stops (blank)

Answer 18

P21

Cycle in S to repair DNA

Question 19

Regulation of MPF to go through G2 checkpoint

Answer 19

• fluctuation of MPF activity and cyclin concentration during the cell cycle
• molecular mechanisms that help regulate the cell cycle

Question 20

Retinoblastoma explanation

Answer 20

• immature cell poliforate out of control
• genes needed for S phase not transcribed
• RB protein phosphorylated by CDK cyclin complex
• EZF - active and never shut off phosphorylation

Question 21

What are some properties of cancer cells?

Answer 21

Environment not the cell is supposed to dictate cell division- not the case in cancer

Question 22

Spread to adjacent tissues and to distant tissues through lymphatic vessels and blood vessels

Answer 22

Malignant

Question 23

Benign

Answer 23

Not cancer- tumor cells grow only locally and cannot spread by invasion of metasis

Question 24

Malignant tumors

Answer 24

Cancer cells invade neighboring tissues, enter blood vessels, and metastasize to different sites (leave!!)

Question 25

Cancer involves

Answer 25

Loss of cell cycle control

Question 26

3 cancer treatments

Answer 26

Radiation: damaged DNA in cancer cells
Chemotherapy: taxol blocks mitosis
Immunotherapy: large area of research